A turbocharger center housing rotating assembly (CHRA) can include a turbine wheel and a compressor wheel attached to a shaft rotatably supported by a ball bearing assembly located in a bore of a center housing. As an example, a rolling element bearing assembly (e.g., or REB cartridge) can include an outer race and an inner race, configured to receive a shaft, where the outer race and the inner race are separated by rolling elements (e.g., balls, rollers, etc.). As another example, a shaft may be configured as an inner race, for example, where rolling elements directly contact the shaft. As an example, a journal bearing can include inner journal surfaces that are spaced an axial distance apart where one inner journal surface may be a compressor side inner journal surface and where another inner journal surface may be a turbine side inner journal surface. In such an example, clearances can exist between an outer surface or surfaces of a shaft and the inner journal surfaces where lubricant may flow to such clearances. In such an example, the journal bearing can support rotation of the shaft where the journal bearing may be rotatable or non-rotatable (e.g., limited in its rotation via an anti-rotation mechanism).
During operation of a turbocharger, lubricant is supplied to a CHRA to lubricate various components and, for example, to act as a medium that can transfer heat energy. An adequate supply of lubricant (e.g., oil, etc.) can help to ensure performance over an expected operational lifetime.